Clicking on a cell to add an event, you get a gtk entry, a button that leads to a separate view to pick the target calendar, and the "Edit details..." and "Add" buttons.

It seems to me that the separate view to pick the target calendar, while fancy, is pointless. It guarantees I'll have to waste two clicks everytime I create a simple event, because the default calendar pick will be wrong 90% of the time... so just put that picker widget's contents directly in the main quick-add popover (unless the user has only one calendar, in which case don't show anything at all!) - after all, you have tons of space available on my screen, make use of it! Size the popover automatically (bug #774951).

Current workflow: 3 clicks + mouse movements required.
Proposed workflow: 1 click required.